<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="./830/js/vue.global.js"></script>
</head>

<body>
    <div class="app">
        ￥：<input type="text" v-model.Number="rmb">
        <br>
         $：<input type="text" v-model="meiyuan">
        <br>
        100人民币 = 14.71美元
    </div>
    <script>
        const moduleA = Vue.createApp({
            data() {
                return {
                    meiyuan: "",
                    rmb: ""
                }
            },
            watch: {
                rmb(newV, oldV) {
                    this.meiyuan = (newV / 6.7981)
                }
            }
        }).mount(".app")
    </script>
</body>

</html>